EVGA GTX580 Classified Hydro-copper in 4-way SLI?

I am designing an "extreme" computing project, and am looking into 4-way SLI. The EVGA GTX580 Classified Hydro-copper is 4-way SLI enabled, but the card (by the look of it) is not truly single-slot. Can other cards fit in between the four cards? I plan on using the EVGA SR-2 motherboard. I just don't want to monopolize all seven PCI-E slots with four video cards (add a TOS-link card, perhaps?).|||Yes it is truly single slot and as far as I know computing projects don't take advantage of SLI